PR fortran/95373 - ICE in build_reference_type, at tree.c:7942

PR fortran/95373 - ICE in build_reference_type, at tree.c:7942

The use of KIND, LEN, RE, and IM inquiry references for applicable intrinsic
types is valid only for suffienctly new Fortran standards.  Add appropriate
checks in the appropriate place.

2020-05-30  Harald Anlauf  <anlauf@gmx.de>

gcc/fortran/
	PR fortran/95373
	* primary.c (is_inquiry_ref): Move validity check of inquiry
	references against selected Fortran standard from here...
	(gfc_match_varspec) ...to here.

gcc/testsuite/
	PR fortran/95373
	* gfortran.dg/pr95373_1.f90: Adjust error messages.
	* gfortran.dg/pr95373_2.f90: Adjust error message.

(cherry picked from commit dd38c765a04d06c775134a135f68b18c3b7c9c78)